The present disclosure relates to downhole tools and, in particular, a swellable screen assembly having inflow control capabilities.
Hydrocarbons can be produced through a wellbore traversing a subterranean formation. In some cases, the formation may be unconsolidated or loosely consolidated. Particulate materials, such as sand, from these types of formations may be produced together with the hydrocarbons. Production of particulate materials presents numerous problems, e.g., particulate materials being produced at the surface, causing abrasive wear to components within a production assembly, partially or fully clogging a production interval, and/or causing damage to production assemblies by collapsing onto part or all of the production assemblies.
Expandable sand control screens can be used to provide stability to a formation to prevent or reduce formation and borehole collapses and also filter particulate materials from hydrocarbon fluids. Expandable sand control screens can include a swellable material, such as a high-swelling rubber, and a filter device on the exterior of the swellable material. The swellable material can be located proximate the production interval and, when activated by a fluid, expand to displace the filter device to the wellbore. The filter device can include perforations through which hydrocarbon fluids from the formation can be received and directed into a production pipe. This type of expandable sand control screen can be effective in filtering and providing formation stability.
In some applications, however, the swellable material may expand into the perforations after contacting the activating fluid. Expanding into the perforations may result in the swellable material partially or completely plugging the perforations of the filter device. Plugged perforations can reduce or prevent hydrocarbon fluids from flowing to an internal flow path of the production pipe, which is generally undesirable. In some cases, a rework of the control screen assembly may be required to alleviate the plugging. Reworks cost substantial time and money because they require suspension of hydrocarbon production for a considerable amount of time and require duplication of work in locating the control screen assembly in the wellbore.
Additionally, in some applications, it is often beneficial to be able to regulate flow of fluids from the subterranean formation into the wellbore while controlling the migration of particulates into the wellbore. Regulating fluids may balance production among zones along the wellbore and mitigate and/or prevent water or gas coning. Further, some fluid flow regulating devices may be designed to maximize oil production and minimize water and/or gas production.
Generally, fluid flow regulation is achieved by directing fluid flow through a nozzle or Venturi device. However, when used in conjunction with applications having low flow rates, as seen with sand screens having pistons, the size of nozzles and Venturi devices need to be small to achieve the desired fluid flow regulation. Because of their size, the nozzles and Venturi devices can be clogged easily, for example, with only a few particulates. Consequently, screen assemblies that can provide radial support to formations, reduce or eliminate plugging, and incorporate fluid flow regulation are desirable.